In late 1937 Lockheed sent a cutaway drawing of the Model 14 to various publications, showing the new aircraft as a civilian aircraft and converted to a light bomber.[4] This attracted the interest of various air forces and in 1938, the British Purchasing Commission sought an American maritime patrol aircraft for the United Kingdom to support the Avro Anson. On 10 December 1938, Lockheed demonstrated a modified version of the Lockheed Model 14 Super Electra commercial airliner, which swiftly went into production as the Hudson Mk I.[5]

A total of 350 Mk I and 20 Mk II Hudsons were supplied (the Mk II had different propellers). These had two fixed Browning machine guns in the nose and two more in the Boulton Paul dorsal turret. The Hudson Mk III added one ventral and two beam machine guns and replaced the 1,100 hp Wright Cyclone 9-cylinder radials with 1,200 hp versions (428 produced).[6]

By February 1939, RAF Hudsons began to be delivered, initially equipping No. 224 Squadron RAF at RAF Leuchars, Scotland in May 1939. By the start of the war in September, 78 Hudsons were in service.[7] Due to the United States' neutrality at that time, early series aircraft were flown to the Canada–US border, landed, and then towed on their wheels over the border into Canada by tractors or horse drawn teams, before then being flown to Royal Canadian Air Force (RCAF) airfields where they were then dismantled and "cocooned" for transport as deck cargo, by ship to Liverpool. The Hudsons were supplied without the Boulton Paul dorsal turret, which was installed on arrival in the United Kingdom.

In 1941, the USAAF began operating the Hudson; the Twin Wasp-powered variant was designated the A-28 (82 acquired) and the Cyclone-powered variant was designated the A-29 (418 acquired). The US Navy operated 20 A-28s, redesignated the PBO-1. A further 300 were built as aircrew trainers, designated the AT-18.

Skilled and experienced pilots found that the Hudson had an exceptional manoeuvrability for a twin-engined aircraft, especially a tight turning circle if either engine was briefly feathered. Saburō Sakai, who would become among the highest-scoring Japanese aces of the war, praised the fighting abilities of a lone, outnumbered Hudson Mk IIIA crew from No. 32 Squadron RAAF on 22 July 1942.[12][13] Hudson A16–201 (bu. no. 41-36979) was intercepted over Buna, New Guinea by nine Mitsubishi A6M Zeroes of the Tainan Kaigun Kōkūtai led by Sakai, who reported that their opponent made many sharp and unexpected turns, engaging the Zero pilots in a turning dogfight for at least 10 minutes. It was only after Sakai himself scored hits on the (rear/upper) gun position that he was able to down the Hudson; its crew was killed. The Japanese pilots were so impressed by their enemy that, after the war's end, Sakai asked Australian researchers to identify the pilot and in 1997 wrote to the Australian government, recommending that Pilot Officer Warren Cowan be "posthumously awarded your country's highest military decoration".[12] Similarly, on 23 November 1942, the crew of a No. 3 Squadron, Royal New Zealand Air Force (RNZAF) Hudson Mk IIIA, NZ2049,[14] (41-46465) after spotting an enemy convoy near Vella Lavella, was engaged by three Japanese floatplane fighters. After skilled evasive manoeuvring at an altitude of less than 50 feet (15 metres), by the Hudson's captain, Flying Officer George Gudsell,[15] the crew returned with no casualties to Henderson Field, Guadalcanal.

Postwar, numbers of Hudsons were sold by the military for civil operation as airliners and survey aircraft. In Australia, East-West Airlines of Tamworth, New South Wales (NSW), operated four Hudsons on scheduled services from Tamworth to many towns in NSW and Queensland between 1950 and 1955.[16] Adastra Aerial Surveys based at Sydney's Mascot Airport operated seven L-414s between 1950 and 1972 on air taxi, survey and photographic flights.[17]

The type formed the basis for development of the Lockheed Ventura resulting in them being withdrawn from front line service from 1944, though many survived the war to be used as civil transports, primarily in Australia and a single example was briefly used as an airline crew trainer in New Zealand.

The Lockheed Hudson features prominently in the Captains of the Clouds (1942). The film starred James Cagney and Dennis Morgan as Canadian bush pilots who do their part in the Second World War as ferry pilots, bringing Hudsons to Britain. The film ends with a depiction of a Hudson ferry flight that mixes authentic live action with studio footage.

Lockheed Hudsons make an appearance in the movie Aerial Gunner (1943). A story of two men at Harlingen (TX) Aerial Gunnery School.

A de-militarized Hudson is flown by Humphrey Bogart's character in Tokyo Joe (1949). Bogart played an ex-World War II pilot attempting to operate a cargo airline in occupied Japan. The Hudson is identifiable by the turret platform at the rear of the fuselage, and by the numerous windows in the cockpit area.

The Lockheed Hudson was featured in the movie The Great Raid as a distraction to Japanese soldiers, although in the real event, a P-61 Black Widow was used. The Hudson was used instead because there were no airworthy Black Widows at the time of the movie's filming.